Nail pulling device



May 26, 1953 w. N. HENRY 2,639,887

NAIL PULLING DEVICE Filed Feb. 16, 1951 2 Sheets-Sheet l as 80 99 g 9392/M 28 1N VEN TOR.

WALTER N. HENRY ATTORNEYS Patented May 26, 1953 UNITED STATES PATENTOFFICE NAIL PULLING DEVICE Walter N. Henry, Dayton, Ohio ApplicationFebruary 16, 1951, Serial No. 211,220

11 Claims.

bedded, particularly where it is desired to leave the surface materialsufiiciently undamaged for reuse.

Such work is ordinarily done by means of hand tools, the use of whichhas a tendency to mar and break the wood so that it cannot be usedagain. Because of the physical strength necessary to use the tools, itis ordinarily required to be done by men. The amount of work that can bedone by each workman each day by the ordinary method, is, moreover,relatively limited.

It is accordingly one of the principal objects of the invention toprovide a power-operated tool for quickly and easily pulling nails andthe like from a surface in which they are embedded and with minimumdamage to the surface.

Another object is to provide power-operated apparatus for opening boxes,crates and the like on a quantity basis in a substantially shorter unittime than heretofore accomplished in order to increase the volume ofwork which may be done in a given time by each operator.

It is a further object of the invention to furnish a device for openingboxes, crates and the like operated by power rather than by muscularstrength, so that it may be used in industry by women and boys. I

Additional objects of the invention are to provide a power-operated nailpulling device which is relatively light in weight, which is relativelysimple yet strong and certain in operation, and which may be produced atreasonable cost.

Other objects and advantages of the invention will be apparent from thefollowing description, the accompanying drawings and the appendedclaims. I

In the drawings Fig. 1 is a side elevation, partly broken away Fig. 5 isa detail perspective view-on an enlarged scale of one of the jaw membersof the device;

Fig. 6 is a detail perspective view of a part of one of thejaw-operating members of the device;

Fig. 7 is a section on the line l'! of Fig. l;

Fig. -8 is a fragmentary section showing the jaws embedded in a surfacesurrounding a nail to be pulled at the beginning of the jaw-closingmovement;

Fig. 9 is a fragmentary section similar to Fig. 8

showing the jaws closed on the, nail, which is partially withdrawn;

Fig. 10 is a side elevation with the casing in section showing therelative positions of the parts at the conclusion of a nail pullingoperation; and

Fig. 11 is an elevational view of another form of construction of thedevice, having a self-contained power source.

Referring to the drawings, which illustrate preferred embodiments ,ofthe invention, the device as shown includes an outer casing 20, shown asin two parts, and an'inner casing 2|, to which are affixed respectivelyhandles 22 and 23, handle 23 projecting through a suitable slot 24 inthe outer casing and being afilxed at its upper end only in order toextend over the outer casing. A rotatable shaft 25 having threadedportion 26 is mounted within inner. casing 2| and is adapted tobe'attached to a power source, not shown, by a flexible drivingconneotion 2'! or other suitable means. The drive shaft 25 is supportedat its upper end by a ball-bearing 28, and at its lower end by anenlarged portion 30 in a bushing 3| press-fitted into a web 32 in theinterior of inner casing 2| and retained in position by a furtherenlargedportion 33 of the shaft. Bearing 28 may be press-fitted into asuitable aperture in the top 34 of inner casing 2| and held in place bycap 35 retained by screws 36 or other suitable means, and as shown,bearing 28 is preferably constructed to serveas both a radial and thrustbearing for shaft 25.

A hammer member 40 is mounted within inner casing 2| for rotational andreciprocating movement in cooperation with an anvil member H and isoperatively connected with shaft 25 by means of a slot 42 which receivesa corresponding flattened end portion 43 of the shaft. The hammer membermay thus slide axially on the shaft but will be rotated by it, and it isnormally biased downward by spring 44 surrounding areduced;

portion of thehammer memberand compressed between the enlarged-portion33 on shaft 25 and an enlarged head portion. of the hammer memher. Theupper end portion of anvil member 4| is also enlarged so that bothmembers fit in guided relation within inner casing 2|, and both thehammer member and anvil member are provided on their adjacent faces withhelically curved cam surfaces to and 5!, respectively, adapted tocooperate with each other alternately as the hammer member 49 is rotatedto force the latter axially of casing 2| and against spring 44 away fromanvil member 4! and then to release the hammer and permit it to strikethe anvil under the urging of spring 44.

The anvil member d] includes a lower portion splined for slidingmovement in the reduced lower end portion 52 of inner casing 2i. d Acarrier member 53 for the nail pulling jaws '55 is secured to the lowerend of the anvil, as b -y the threaded connection at 58, for movementtherewith as a unit, and these parts are normally biased downwardly bythe spring 5'! seating against shoulder portions 'on the member 53 andinner casing 2| 'as clearly shown in Fig. 2. The lower end of carriermember 53 is slotted to form a fork for receiving jaws '55, which arepivoted therein by means of pins 58 in bores '59 and are normally biasedto open position by a spring 60 as shown in Fig. 2, and the jaws may beprovided with serrated nail gripping edges 61 (Fig.5).

The jaws 55 are adapted to be closed-into nail gripping position by aninwardly tapered collet portion '65 at the lower end of outer casing. 26which operates the jaws through a pair of fingers 6t pivoted at theirupper ends by pins 61 in slots at either side of-casingzl. At its lowerend, each finger 86 (Fig. 6) carries a roller 70 for reducing frictionwith the collet 65, and the inner; side of the lower end of each finger66 is channeled at H for guided engagement with lugs 'or pads I2 on thebacks of the jaws 55 which fit slid'ably within the channels '11. Thusif outer casing is moved 'down'wa'rdlywith respectto the inner casing,the'collet 65 will press fingers ts inwardly against jaws 55 and therebyforce the nail gripping lower portions of the J'aw's towards-each otherand into grippingposition.

A selectively operable driving connection is provided for causingrelative axial-movement of the inner and outer casings to efiect closingof jaws 55 as described, and thereafter to cause the nail gripped in the'closed'jaws to be withdrawn. This connection includes a partlyhollow'block l5 straddling shaft and having a threaded halfcircularportion 17 adapted to engage the thread ed portion 26- ofshaft "25-. 'Atone end block 5 5 includes upwardly extending arms '18 in which a lever79 is pivotally mounted at 80-, "and at itsopposite end block 15includes a 'pinp ruon 31-. Block i5 extends through projections '82 and83 on the-wallof casing 20, projection sensin pro= vid'ed with a cap-84. A'spri'ng B5 is mounted on pin 81 between the end ofprojection 83and a washer 86 held on the end of pin B'I bymearis such as a cotter pin8l to bias block 15 to the right as viewed-in Fig. l and thus todisengage threads 11 from-the threaded pdrtion ze-o'r the shaft.

A b-lock eo is slidably-r'eeeived within block it. and. it includes apin portion 91 which extends through a slot "92 in lever 79 and th-rougha plate 93 held. between the arms TB- outwardly of lever 79. At itsihnereride, block 90 "inelude's'ath half circular portion 94 adapted toengage the threads '25. on shaft '25. A 95 is mounted on pin'9 I betweenplate 93 and a wa er J6 andcotter. pin 911011 pin. 9 I to bias block- 90normally:

' shait 25 revolving, the blocks will be caused to travel along theshaft and to carry outer casing 20 downwardly with respect to innercasing 21. (lasing 2l has slots I00 on opposite sides to receive blocks(5 and 90 during this movement, as well as the slot 24 for similarlyreceiving handle 23 as described.

"In operation, the operator holds the device in position substantiallyperpendicular to the surface in which the nail is embedded, with theopen jaws on either side of A the head of the nail. Slight pressureforces the jaw assembly and a'nvil 'member 4! axially inward against thepressure of spring 5?, bringing the cam surfaces 50 and '5! of hammer M8and anvil il into contact. As hammer member 40 is rotated rapidly byshaft 25, the cam surfaces cooperate first to force it away from theanvil member, compressing spring M, as shown in Fig. 2, and then torelease it to be driven sharply against anvil member 4| by the releaseof this spring, producing a reciprocating hammering action to force jaws55 into the surface against which the jaws rest as shown in Fig. 8 inposition to grip the nail when thejaws are closed.

In order to close the jaws around the nail and to .extract it, theoperator then causes outer casing 28 to move axially of inner casing 2|by pressing the free end of lever '59 toward the casing, causing blocks75 and EN! to move inwardly into cooperative engagement with thethreaded portion 26 of shaft '25 and to travel downward along therotating shaft as described, outer casing 20 serving during thismovement both as a jaw-closing member and as a withdrawing member. Ascasing 20 moves downward, the jaws are caused to close into grippingrelation with the nail by the collet 65 as shown in Figs. 8 and 9. As itcontinues its downward inotion, its lower end comes into contact withthe surface surrounding the nail and causes inner casing 2| and theclosed jaws to move away from such surface until the nail is fullywithdrawn (Fig. 10). The length of threaded portion 26 should he suchthat the closed blocks 75 and 90V will ride on the lower end thereofwhen withdrawal is completed. The operator then, by releasing lever T5,allows the blocks to be separated by the action of springs and 95, andreturns outer casing 20 manually by means of handles 22 and 23 to theposition of Fig. 1. As jaws 55 are released from the pressure of collet65 they are opened by spring 50, and the withdrawn nail drops out.

The area of the lower end. of casing 20 pressing against the surfacesurrounding the. nail while it is being withdrawn is sufficiently broadthat there is little if any tendency for it to mark the surface.Additionally, all of the force used in extracting the nail is exertedoutwardly, so that any tendency to push the nail sidewise and thus toincrease friction during extraction, as is the case with the hand toolsnormally em; ployed, is avoided. There is accordingly a minimum tendencyto mar, break or otherwise to .spoil thew'ood or other suifaceinwhichthe nail is vimbedded, permittingsuch material to be reused. Thususe of the invention will greatly speed up the operation of withdrawingnails and permit substantial increase in the rate of work of anoperator. Furthermore, since the physical strength necessary foroperating the device is substantially only that necessary to hold it inposition and it is relatively light in weight, only slight physicalstrength is required for its use, and it may easily be used by women andboys.

It is preferable that hammer member 40 and anvil member 4| shouldoperate in a lubricating bath, and inner casing 2| is accordingly shownas being formed in two sections connected by a threaded connection at [Mto provide for adding lubricant when necessary, and also for simplicityin assembly. It may be advisable also for the lower portion of outercasing 20 to be made from steel or other material different from that ofthe upper portion, and as noted, outer casing 20 is similarly shown asbeing in two sections connected by a threaded connection at I02.

It is apparent that the force of the blows by hammer member 40 on anvilmember 4| will depend on such factors as the weight of the hammermember, the strength of the spring 44, the length of the stroke, and thespeed of rotation of shaft 25. It has been found in practice that ahammer member weighing slightly more than A; pound, rotated at a speedof approximately 1000 R. P. M. and with two earns 50 and 5| on each ofthe respective cam surfaces having a depth between their high and lowpoints of approximately one-half inch, in cooperation with a springexerting a pressure of approximately 60-80 lbs. when compressed, givessatisfactory results.

Fig. 11 shows a nail .pulling device similar..to that described inconnection with Figs. 1 to'lO and including similar outer and innercasings l20 and IN respectively. However, instead of a flexibleconnection to the drive shaft from an external drive source, Fig. 11shows a motor I22 mounted directly on the upper end of the inner casing,either an electric or air motor being satisfactory. The construction andoperation of this form of the invention is otherwise substantially thesame as already described in connection with Figs. 1 to 10.

While the forms of apparatus herein described constitute preferredembodiments of the invention, it is to be understood that the inventionis not limited to these precise forms of apparatus, and that changes maybe made therein without departing from the scope of the invention whichis defined in the appended claims.

What is claimed is:

l. A power-operated nail pulling device comprising a casing, an anvilmovable in said casing, nail-gripping jaws carried by said anvil andprojecting from said casing, a drive shaft rotatable in said casing,means for connecting said drive shaft to a power source for rotationthereby, a driving member for said anvil mounted for reciprocation insaid casing in response torota-- tion of said drive shaft for drivingsaid anvil in a direction to force said jaws into the surfacesurrounding a nail to be pulled, a withdrawing member carried by saidcasing and extending adjacent said jaws in initially spaced relationwith said surface, means for causing the closing of said jaws to gripsaid nail, and means for selectively connecting said drive shaft to saidwithdrawing member for causing relative movement thereof toward saidsurface-and corresponding movement of said jaws in gripping relationwith said nail away from said surface.

2. A power-operated nail pulling device comprising a casing, an anvilmovable in said cas-- ing, nail-gripping jaws carried by said anvil andprojecting from said casing, a drive shaft rotatable in said casing,means for connecting said drive shaft to a power source for rotationthereby, a driving member for said anvil mounted for reciprocation insaid casing on rotation of said drive shaft for driving said anvil in adirection to force said jaws into the surface surrounding a nail to bepulled, a withdrawing member carried by said casing and extendingadjacent said jaws in initially spaced relation with said surface, meansoperably connected with said drive shaft for causing the closing of saidjaws to grip said nail, and means operably connected with said driveshaft for causing relative movement of said withdrawing member towardsaid surface and corresponding movement of said jaws in grippingrelation with said nail away from said surface.

3. A nail pulling device comprising an anvil member, normally opennail-gripping jaws carried by said anvil member, a hammer memberadjacent said anvil member and reciprocable with respect thereto, adrive shaft, means connected with said drive shaft for driving saidhammer member against said anvil member in a direction to force saidjaws into the surface surrounding a nail to be pulled, a withdrawingmember adjacent said jaws and initially spaced from said surface, saidwithdrawing member having a portion adapted on movement thereof towardsaid surface to close said jaws to grip said nail, said withdrawingmember having another portion adapted on movement thereof toward saidsurface to abut against said surface and to press said jaws in grippingrelation with said nail away from said surface, and means forselectively connecting said withdrawing member with said drive shaft.

4. A nail-pulling device adapted for use with a power source, comprisinga rotatable shaft adapted to be connected to said power source, adriving member operably connected with said shaft for rotation thereby,an anvil member adjacent said driving member, normally open nailgrippingjaws carried by said anvil member, means for biasing said driving membertoward said anvil member, means on said driving member and said anvilmember adapted to cooperate with said biasing means on rotation of saiddriving member for driving said anvil member in a direction to forcesaid jaws into the surface SUI",

rounding a nail to be pulled, means for selectively closing said jaws ingripping relation with said nail, means movable relatively to said jawsfor direct engagement with said surface to force said jaws and said nailaway from said surface, and means for selectively connecting saidmovable means with said power source for causing said relative movementof said jaws and said movable means.

5. A power-operated device for pulling nails comprising a rotatableshaft adapted to be connected to a power source, a hammer member on saidshaft adapted to rotate therewith and to move axially thereon, an anvilmember adjacent said hammer member, a plurality of normally opennail-gripping jaws supported for movement with' said anvil member, meansbiasing said hammer member toward said anvil member, complementaryportions on said hammer member and;

aeeaeer said anvil member adapted to cooperate with said biasing meansto effect reciprocating move-- ment of said hammer member with respectto said anvil member upon rotation of said shaft to drive said jaws intothe surface adjacent a nail to be pulled, a withdrawing member adjacentsaid jaws in initially spaced relation with said surface, means foroperation by said shaft to close said jaws in gripping relation withsaidnail, means for operation by said shaft for cansing relativemovement or said withdrawing member toward said surface andcorresponding move merit of said closed jaws and said nail awayfro'msaid surface to extract said nail therefrom, and means for releasablyconnecting said shaft with said jaw-closing means and with saidwithdrawing member.

'6. A power-operated device for pulling -nails comprising a rotatableshaft adapted. to be con nected to a power source, a hammer member onsaid shaft adapted to rotate therewith and to move axially thereon, an"anvil member adjacent said hammer member, a plurality of normally opennail-gripping jaws supported for movement with said anvil member, meansbiasing said-hammer member toward said anvil member, comp-1ementary camportions on said hammer member and said anvil member adaptedt'ocooperate with said biasing means to effect reciprocating movement ofsaid hammer member with respect to said anvil member upon rotation ofsaid "shaft to drive said jaws into the-surface adjacent a, nail to bepulled, a casing supporting said shaft "and said hammer member and anvilmember, means slidable on said casing forming a collet for closing saidjaws in gripping relation with 'saidnai-l, and means forming aselectively operable driving connection between said shaft and saidcollet causing said collet to move first into jaw-closing relation withsaid jaws and thereafter to move beyond said jaws and against saidsurface to force said jaws and nail away from-said surface.

7. In a power-operated nail puller, a casing, a rotatable shaft in saidcasing adapted to be connected to a power source, a hammer member onsaid shaft adapted to rotate with said shaft and to move axiallythereon, an anvil member in said casing adjacent said hammer member,normally open nail-gripping jaws carried by said anvil member, meansbiasing said hammer member toward said anvil member, means cooperatiingwith said biasing means to effect reciprocating movement of said hammermember with respect to said anvil member upon relative ro't'ativemovement of said hammermember and said anvil member to drive saidnail-gripping jaws into the surface adjacent a nail to be pulled,jawclosing means supported by said casing for first closing said jaws togrip said nail and for thereafter forcing said jaws and said nail awayfrom said surface to withdraw said nail, and selectively operable meansfor connecting said jaw-closing means with said shaft.

8. A nail pulling device adapted for use with a power source, comprisinga rotatable shaft hav ing a threaded portion thereon, means forconnecting said shaft to said power source, axhammer member on saidshaft adapted to rotate therewith and to move axially thereon, an anvilmember adjacent said hammer member, normally open nail-gripping jawssupported for movement with said anvil member, means for effectingreciprocating movement of saidshammer member with respect to said anvilmember upon. rotation of said shaft "to drive said Jaws intothe.

serrate adjacent a hall to be pulled, a member" for "closing saidjaws-supported for axial movement with respect to said shaft, threadedmembers supported on saidclosing member for movement therewith andnormally spaced from said shaft, and means for bringing said threadedmembers into cooperative engagement with said threaded portion of saidshaft for causing said axial movement of said closing member to closesaid jaws on said nail and to press said closed jaws and nail away fromsaidsurface.

9. A power-operatedhail-pulling device comprising an outer casing, aninner casing adapted for aide-l movement within said outer casing, arotatable shaft within said inner casing adapted to be connected to apowerseurce, an anvil supported in-said inner casing, for limited axialmove ment therein, normally open nail-gripping jaws supported by saidanvil, a hammer adjacent said anvil mounted for reciprocating axialmovement onsaid shaft and adapted to rotate with said shaft, meansbiasing said hammer toward said anvil, earn means on adjacent faces ofsaid hammer and said anvil-cooperating with said biasing means to effectreciprocating movement of said.

hammer toward and away from said anvil upon rotation of said shaft fordriving said jaws into the'surfacesurrounding a nail to be pulled, meansfor "effecting relative axialimo'vement of said outer casing andsaidinner casinguponrotation of said shaft, and means for causing said jawsto grip and to withdraw said nail upon said relative axialm ovement'o'fsaidouter andsaid inner casings.

10-. A po'wer-operated'inail puller comprising a casing, a rotatableshaft insaid-cas'ing, saidshaft having a threadedpdfiion thereon, meansfor connecting said shaft with a power source, a hammer member on. saidshaft adapted for axial movement thereon and for rotation therewith, an

anvil. member. in said-casing adjacent said hammer member, saidiharnmer'member and said anvil member including-cooperating cam surfaces onadjacent facesxthereof, normally open nail-gripping ijaws carried-bysaid-anvil member, means biasing said hammer member toward said anvilmember and: adapted to cooperate with said. cam surfaces-for effectingreciprocating axial movement of said -hammerimember with respect to saidanvil member upon rotation'of said shaft to drivesai dopeninailagripping jaws into the surface surrounding anail to be pulled,a member carried by said casing initially spaced relation with saidsurface adapted to move axially of said shaf-ttoward-said surface-forclosing said jaws, said member having a portion thereof adapted on saidaxial movement to press against said surface and to force said jaws ingripping relation with saidv nail away from said surface, and threadedmeans carried by said axially movable member, for releasable engagementwith said threaded portion of said shaft'to cause said axial movement ofsaid movable member.

11. In a, power-operated -nail puller, a casing, a rotatable shaft insaid casing adapted 'to be connected toatpower source andhawihgathrw'dedportion. thereon, aYhar-nmer member on said shaft adapted'to rotatewithssaid shaft and to move axially thereon, an anvil member in saidcasing adjacent said hammer member, normally open nail-grippingmeanscarried by said anvil member, means biasing, said hammer membertoward said anvil member, means cooperating with said biasing means .to,effect reciprocating movement of saidfhammenmember with respect tosaidanvil member upon relative rotative. --movement of said hammer memberand said anvil member to drive said nail-gripping means into the surfaceadjacent a nail to be pulled, a collet supported by said casing foraxial movement with respect to said shaft to close said gripping means,blocks supported for movement with said coilet and normally spaced fromsaid threaded portion of said shaft, said blocks having threadedportions for cooperative gripping engagement with said threaded portionof said shaft on movement into engagement therewith, and a lever forefiecting movement of said blocks into said cooperative grippingengagement with said threaded portion of said shaft for causing saidaxial movement of said coliet to close said nail-gripping means on saidnail and to press said closed nail-gripping means away from said surfaceto withdraw said nail.

WALTER N. HENRY.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 754,754 Dudly Mar. 15, 1904 2,570,915 Buck Oct. 9, 1951-

